Single versus multiple exposures of LLLT will be tested in the endometrial culture plates and will be compared to control group not exposed to laser. Comparison between single session exposure and multiple sessions' exposure is important in order to determine the benefits over the risk of multiple exposures sessions in thin endometrium in vivo, being an invasive procedure and requiring a fibro-optic probe insertion inside the uterus which might cause some discomfort to the patient and could be affected by patient's compliance.